UPDATED: Guillermo del Toro's first big-budget tentpole is opening in 38 foreign markets this weekend, coinciding with the movie's North American launch Thursday night.

Warner Bros. and Legendary Pictures' Pacific Rim got off to a mixed start at the international box office on Thursday, grossing a stellar $1.5 million in South Korea, but earning only $610,000 in Australia to come in No. 4 behind the opening day of The Heat and holdovers Despicable Me 2 and Monsters University.

As in South Korea, the sci-fi epic did well in New Zealand, where it opened to roughly $100,000.

Marking Guillermo del Toro's first big-budget tentpole, Pacific Rim is opening in 38 foreign territories this weekend, representing roughly 45 percent of the international marketplace. That includes six of the 12 major territories, including the U.K., Italy, Russia, South Korea and Australia.

Warners and Legendary -- which footed much of the $190 million production budget -- are banking heavily on a strong international run, considering that action tentpoles often do much bigger business overseas than they do in North America.

Pacific Rim, about world leaders uniting to fight off giant alien reptiles with equally giant robots named Jaegers, was tailor-made for foreign audiences, featuring an international cast as well as an Australian, Russian, Chinese and Japanese Jaeger.

Pacific Rim's soft start in Australia is unwelcome news for the filmmakers, although it could make up ground as the weekend unfolds.

In South Korea, it opened 209 percent ahead of Rise of the Planet of the Apes, which went on to gross north of $300 million internationally and 161 percent ahead of Clash of the Titans, which cumed $332 million internationally. And it opened on par with Brad Pitt's World War Z, which is still in release.

Pacific Rim launches on Thursday night in North America, where it has been plagued by soft tracking. However, Legendary and Warners are hopeful that the movie defies tracking and opens well north of $40 million.